fluent-bit: add package

fluent-bit: add package

* add package fluent-bit v3.1.3
* test performed
  - compile-test
  - run-test on target

* fluent-bit package is added to provide another option for
  log collection and management. It integrates well with
  a wide variety of environments and deployments. It is widely
  used by a number of organizations and is supported across a
  variety of platforms. Integrating it to make it available as
  an openwrt package.

Signed-off-by: Rahul Thakur <rahul.thakur@iopsys.eu>